Chapter 11, Problem 73A

(a)

Interpretation Introduction

Interpretation:

Identification of the atom through ground state electronic configuration.

Concept Introduction:

From outer electronic configuration group number of the element can be determined.

From total number of the electrons atomic number of the element can be known (for neutral atom only. Hence we can identify the element.

Answer to Problem 73A

The element is sulphur $(Z=16)$ .

Explanation of Solution

The outer electronic configuration is $n{s}^{2}n{p}^4$ . Hence the element belongs to Oxygen family.

Complete electronic configuration is $[Ne]3s^{2}3p^4$ . So, atomic number of the element is 16.

Hence the element is sulphur.

(b)

Interpretation Introduction

Interpretation:

Identification of the atom through excited state electronic configuration.

Concept Introduction:

When an atom is excited electrons are promoted from lower energy level to higher energy level.

Answer to Problem 73A

The element is Nitrogen (N)

Explanation of Solution

From the orbital diagram it is obvious that one electron is promoted from $2s$ to $2p$ orbital.

Ground state electronic configuration of the atom is $1s^{2}2s^{2}2p^3$ . So, the atomic number of the element is 7.

Hence, the atom is nitrogen.

(c)

Interpretation Introduction

Interpretation:

Identification of the atom through electronic configuration of its anion.

Concept Introduction:

Anion with $-1$ charge means one electron is added to the neutral element. Removal of one electron from outer orbital will give total number of electrons in neutral atom.

Answer to Problem 73A

The element is Selenium (Se) and the ion is ${\text{Se}}^{-1}$ .

Explanation of Solution

The electronic configuration of the ion is $[Ar]4s^{2}4p^4$ .

So, to get the neutral atom we have to remove one electron from the $4p$ orbital.

Electronic configuration of the neutral atom is $[Ar]4s^{2}4p^3$ .

So, the atomic number of the element is 33 and hence the element is Se.

The ion is ${\text{Se}}^{-1}$ .